Method and system for identity-based authentication of virtual machines

ABSTRACT

A cloud computing system configured to run virtual machine instances is disclosed. The cloud computing system assigns an identity to each virtual machine instance. When the virtual machine instance accesses initial configuration resources, it provides this identity to the resources to authenticate itself. This allows for flexible and extensible initial configuration of virtual machine instances.

BACKGROUND

The present disclosure relates generally to cloud computing, and moreparticularly to using identity information for authentication of virtualmachines.

Cloud computing services can provide computational capacity, dataaccess, networking/routing and storage services via a large pool ofshared resources operated by a cloud computing provider. Because thecomputing resources are delivered over a network, cloud computing islocation-independent computing, with all resources being provided toend-users on demand with control of the physical resources separatedfrom control of the computing resources.

Originally the term cloud came from a diagram that contained acloud-like shape to contain the services that afforded computing powerthat was harnessed to get work done. Much like the electrical power wereceive each day, cloud computing is a model for enabling access to ashared collection of computing resources—networks for transfer, serversfor storage, and applications or services for completing work. Morespecifically, the term “cloud computing” describes a consumption anddelivery model for IT services based on the Internet, and it typicallyinvolves over-the-Internet provisioning of dynamically scalable andoften virtualized resources. This frequently takes the form of web-basedtools or applications that users can access and use through a webbrowser as if it was a program installed locally on their own computer.Details are abstracted from consumers, who no longer have need forexpertise in, or control over, the technology infrastructure “in thecloud” that supports them. Most cloud computing infrastructures consistof services delivered through common centers and built on servers.Clouds often appear as single points of access for consumers' computingneeds, and do not require end-user knowledge of the physical locationand configuration of the system that delivers the services.

The utility model of cloud computing is useful because many of thecomputers in place in data centers today are underutilized in computingpower and networking bandwidth. People may briefly need a large amountof computing capacity to complete a computation for example, but may notneed the computing power once the computation is done. The cloudcomputing utility model provides computing resources on an on-demandbasis with the flexibility to bring it up or down through automation orwith little intervention.

As a result of the utility model of cloud computing, there are a numberof aspects of cloud-based systems that can present challenges toexisting application infrastructure. First, clouds should enableself-service, so that users can provision servers and networks withlittle human intervention. Second, network access is necessary. Becausecomputational resources are delivered over the network, the individualservice endpoints need to be network-addressable over standard protocolsand through standardized mechanisms. Third, multi-tenancy. Clouds aredesigned to serve multiple consumers according to demand, and it isimportant that resources be shared fairly and that individual users notsuffer performance degradation. Fourth, elasticity. Clouds are designedfor rapid creation and destruction of computing resources, typicallybased upon virtual containers. Provisioning these different types ofresources must be rapid and scale up or down based on need. Further, thecloud itself as well as applications that use cloud computing resourcesmust be prepared for impermanent, fungible resources; application orcloud state must be explicitly managed because there is no guaranteedpermanence of the infrastructure. Fifth, clouds typically providemetered or measured service—like utilities that are paid for by thehour, clouds should optimize resource use and control it for the levelof service or type of servers such as storage or processing.

Cloud computing offers different service models depending on thecapabilities a consumer may require, including SaaS, PaaS, andIaaS-style clouds. SaaS (Software as a Service) clouds provide the usersthe ability to use software over the network and on a distributed basis.SaaS clouds typically do not expose any of the underlying cloudinfrastructure to the user. PaaS (Platform as a Service) clouds provideusers the ability to deploy applications through a programming languageor tools supported by the cloud platform provider. Users interact withthe cloud through standardized APIs, but the actual cloud mechanisms areabstracted away. Finally, IaaS (Infrastructure as a Service) cloudsprovide computer resources that mimic physical resources, such ascomputer instances, network connections, and storage devices. The actualscaling of the instances may be hidden from the developer, but users arerequired to control the scaling infrastructure.

One way in which different cloud computing systems may differ from eachother is in how they deal with control of the underlying hardware andprivacy of data. The different approaches are sometimes referred to a“public clouds,” “private clouds,” “hybrid clouds,” and “multi-vendorclouds.” A public cloud has an infrastructure that is available to thegeneral public or a large industry group and is likely owned by a cloudservices company. A private cloud operates for a single organization,but can be managed on-premise or off-premise. A hybrid cloud can be adeployment model, as a composition of both public and private clouds, ora hybrid model for cloud computing may involve both virtual and physicalservers. A multi-vendor cloud is a hybrid cloud that may involvemultiple public clouds, multiple private clouds, or some mixture.

Cloud computing systems include virtual machines that are instantiatedfrom virtual machine images. One problem faced in cloud computingsystems is handling security for newly instantiated virtual machineinstances. The obvious solution to this problem is to storeauthentication information (e.g., ssh keys, login credentials, etc)directly in the virtual machine image. This would allow a virtualmachine image to be authenticated immediately following instantiation.However, this type of authentication, based on the virtual machineinstance's “possession” of a security credential, is inherentlyinsecure; as the virtual machine images may be under the control of aparty other than the one that created the image (e.g. the cloud servicesprovider). So embedding login credentials in the image is not apractical solution. Another solution is the concept of administrativevolumes, which are read-only information sources mounted automaticallyby new virtual machines. A newly instantiated virtual machine can readthese volumes to obtain its initial configuration. However, read-onlyvolumes are insufficient to provide all information needed by the newlyinstantiated virtual machine. For example, some virtual machines needinformation about the current state of the network upon instantiation.Storing this information in an administrative volume would require thatvolume to be constantly updated as network conditions changed, leadingto the possibility of the virtual machine receiving stale data.

Accordingly, a system and method to authenticate newly instantiatedvirtual machine instances based on their identity would be desirable.Such a solution provides an appropriate level of security and a higherdegree of flexibility to react to existing conditions in a cloudcomputing system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating an external view of a cloudcomputing system.

FIG. 2 is a schematic view illustrating an information processing systemas used in various embodiments.

FIG. 3 is a virtual machine management system as used in variousembodiments.

FIG. 4 a is a diagram showing types of network access available tovirtual machines in a cloud computing system according to variousembodiments.

FIG. 4 b is a flowchart showing the establishment of a VLAN for aproject according to various embodiments.

FIG. 5 a shows a message service system according to variousembodiments.

FIG. 5 b is a diagram showing how a directed message is sent using themessage service according to various embodiments.

FIG. 5 c is a diagram showing how a broadcast message is sent using themessage service according to various embodiments.

FIG. 6 shows IaaS-style computational cloud service according to variousembodiments.

FIG. 7 is a diagram showing the process of instantiating, launching andauthenticating a VM instance according to various embodiments.

FIG. 8 is a flowchart showing a method of instantiating, launching andauthenticating a VM instance according to various embodiments.

SUMMARY OF THE INVENTION

In one embodiment, a cloud computing system includes a resource havingconfiguration information. The system further includes a virtual machineinstance operably coupled to the resource, wherein the virtual machineinstance has an identity. The system further includes an authenticationmanager configured to control access by the virtual machine instance tothe resource based on the identity of the virtual machine instance.

In another embodiment, a method for controlling access to a resourceincludes instantiating a virtual machine instance. The method furtherincludes assigning an identity to the virtual machine instance. Themethod further includes receiving a request for access to the resourcefrom the virtual machine instance, the request including the identity ofthe virtual machine instance. The method further includes determiningwhether the virtual machine instance may access the resource based onthe identity in the request.

In another embodiment, a method for controlling access of virtualmachines to resources in a cloud computing system includes receiving arequest to instantiate a virtual machine instance. The method furtherincludes instantiating the virtual machine instance. The method furtherincludes assigning the virtual machine instance a unique, immutableattribute. The method further includes performing an initial boot of thevirtual machine instance. The method further includes receiving arequest from the virtual machine instance to access a resource, therequest including the unique, immutable attribute. The method furtherincludes determining whether to allow or deny the request from thevirtual machine instance to access the resource based on permissionsconfigured for the unique, immutable attribute assigned to the virtualmachine instance. If it is determined that the request should beallowed, the method further includes transmitting a response to thevirtual machine instance. If it is determined that the request shouldnot be allowed, the method further includes transmitting an errorresponse to the virtual machine instance.

DETAILED DESCRIPTION

The following disclosure has reference to computing services deliveredon top of a cloud architecture.

Referring now to FIG. 1, an external view of one embodiment of a cloudcomputing system 110 is illustrated. The cloud computing system 110includes a user device 102 connected to a network 104 such as, forexample, a Transport Control Protocol/Internet Protocol (TCP/IP) network(e.g., the Internet.) The user device 102 is coupled to the cloudcomputing system 110 via one or more service endpoints 112. Depending onthe type of cloud service provided, these endpoints give varying amountsof control relative to the provisioning of resources within the cloudcomputing system 110. For example, SaaS endpoint 112 a will typicallyonly give information and access relative to the application running onthe cloud storage system, and the scaling and processing aspects of thecloud computing system will be obscured from the user. PaaS endpoint 112b will typically give an abstract Application Programming Interface(API) that allows developers to declaratively request or command thebackend storage, computation, and scaling resources provided by thecloud, without giving exact control to the user. IaaS endpoint 112 cwill typically provide the ability to directly request the provisioningof resources, such as computation units (typically virtual machines),software-defined or software-controlled network elements like routers,switches, domain name servers, etc., file or object storage facilities,authorization services, database services, queue services and endpoints,etc. In addition, users interacting with an IaaS cloud are typicallyable to provide virtual machine images that have been customized foruser-specific functions. This allows the cloud computing system 110 tobe used for new, user-defined services without requiring specificsupport.

It is important to recognize that the control allowed via an IaaSendpoint is not complete. Within the cloud computing system 110 are oneor more cloud controllers 120 (running what is sometimes called a “cloudoperating system”) that work on an even lower level, interacting withphysical machines, managing the contradictory demands of themulti-tenant cloud computing system 110. The workings of the cloudcontrollers 120 are typically not exposed outside of the cloud computingsystem 110, even in an IaaS context. In one embodiment, the commandsreceived through one of the service endpoints 112 are then routed viaone or more internal networks 114. The internal network 114 couples thedifferent services to each other. The internal network 114 may encompassvarious protocols or services, including but not limited to electrical,optical, or wireless connections at the physical layer; Ethernet, Fibrechannel, ATM, and SONET at the MAC layer; TCP, UDP, ZeroMQ or otherservices at the connection layer; and XMPP, HTTP, AMPQ, STOMP, SMS,SMTP, SNMP, or other standards at the protocol layer. The internalnetwork 114 is typically not exposed outside the cloud computing system,except to the extent that one or more virtual networks 116 may beexposed that control the internal routing according to various rules.The virtual networks 116 typically do not expose as much complexity asmay exist in the actual internal network 114; but varying levels ofgranularity can be exposed to the control of the user, particularly inIaaS services.

In one or more embodiments, it may be useful to include variousprocessing or routing nodes in the network layers 114 and 116, such asproxy/gateway 118. Other types of processing or routing nodes mayinclude switches, routers, switch fabrics, caches, format modifiers, orcorrelators. These processing and routing nodes may or may not bevisible to the outside. It is typical that one level of processing orrouting nodes may be internal only, coupled to the internal network 114,whereas other types of network services may be defined by or accessibleto users, and show up in one or more virtual networks 116. Either of theinternal network 114 or the virtual networks 116 may be encrypted orauthenticated according to the protocols and services described below.

In various embodiments, one or more parts of the cloud computing system110 may be disposed on a single host. Accordingly, some of the “network”layers 114 and 116 may be composed of an internal call graph,inter-process communication (IPC), or a shared memory communicationsystem.

Once a communication passes from the endpoints via a network layer 114or 116, as well as possibly via one or more switches or processingdevices 118, it is received by one or more applicable cloud controllers120. The cloud controllers 120 are responsible for interpreting themessage and coordinating the performance of the necessary correspondingservices, returning a response if necessary. Although the cloudcontrollers 120 may provide services directly, more typically the cloudcontrollers 120 are in operative contact with the service resources 130necessary to provide the corresponding services. For example, it ispossible for different services to be provided at different levels ofabstraction. For example, a “compute” service 130 a may work at an IaaSlevel, allowing the creation and control of user-defined virtualcomputing resources. In the same cloud computing system 110, aPaaS-level object storage service 130 b may provide a declarativestorage API, and a SaaS-level Queue service 130 c, DNS service 130 d, orDatabase service 130 e may provide application services without exposingany of the underlying scaling or computational resources. Other servicesare contemplated as discussed in detail below.

In various embodiments, various cloud computing services or the cloudcomputing system itself may require a message passing system. Themessage routing service 140 is available to address this need, but it isnot a required part of the system architecture in at least oneembodiment. In one embodiment, the message routing service is used totransfer messages from one component to another without explicitlylinking the state of the two components. Note that this message routingservice 140 may or may not be available for user-addressable systems; inone preferred embodiment, there is a separation between storage forcloud service state and for user data, including user service state.

In various embodiments, various cloud computing services or the cloudcomputing system itself may require a persistent storage for systemstate. The data store 150 is available to address this need, but it isnot a required part of the system architecture in at least oneembodiment. In one embodiment, various aspects of system state are savedin redundant databases on various hosts or as special files in an objectstorage service. In a second embodiment, a relational database serviceis used to store system state. In a third embodiment, a column, graph,or document-oriented database is used. Note that this persistent storagemay or may not be available for user-addressable systems; in onepreferred embodiment, there is a separation between storage for cloudservice state and for user data, including user service state.

In various embodiments, it may be useful for the cloud computing system110 to have a system controller 160. In one embodiment, the systemcontroller 160 is similar to the cloud computing controllers 120, exceptthat it is used to control or direct operations at the level of thecloud computing system 110 rather than at the level of an individualservice.

For clarity of discussion above, only one user device 102 has beenillustrated as connected to the cloud computing system 110, and thediscussion generally referred to receiving a communication from outsidethe cloud computing system, routing it to a cloud controller 120, andcoordinating processing of the message via a service 130, theinfrastructure described is also equally available for sending outmessages. These messages may be sent out as replies to previouscommunications, or they may be internally sourced. Routing messages froma particular service 130 to a user device 102 is accomplished in thesame manner as receiving a message from user device 102 to a service130, just in reverse. The precise manner of receiving, processing,responding, and sending messages is described below with reference tothe various discussed service embodiments. One of skill in the art willrecognize, however, that a plurality of user devices 102 may, andtypically will, be connected to the cloud computing system 110 and thateach element or set of elements within the cloud computing system isreplicable as necessary. Further, the cloud computing system 110,whether or not it has one endpoint or multiple endpoints, is expected toencompass embodiments including public clouds, private clouds, hybridclouds, and multi-vendor clouds.

Each of the user device 102, the cloud computing system 110, theendpoints 112, the network switches and processing nodes 118, the cloudcontrollers 120 and the cloud services 130 typically include arespective information processing system, a subsystem, or a part of asubsystem for executing processes and performing operations (e.g.,processing or communicating information). An information processingsystem is an electronic device capable of processing, executing orotherwise handling information, such as a computer. FIG. 2 shows aninformation processing system 210 that is representative of one of, or aportion of, the information processing systems described above.

Referring now to FIG. 2, diagram 200 shows an information processingsystem 210 configured to host one or more virtual machines, coupled to anetwork 205. The network 205 could be one or both of the networks 114and 116 described above. An information processing system is anelectronic device capable of processing, executing or otherwise handlinginformation. Examples of information processing systems include a servercomputer, a personal computer (e.g., a desktop computer or a portablecomputer such as, for example, a laptop computer), a handheld computer,and/or a variety of other information handling systems known in the art.The information processing system 210 shown is representative of, oneof, or a portion of, the information processing systems described above.

The information processing system 210 may include any or all of thefollowing: (a) a processor 212 for executing and otherwise processinginstructions, (b) one or more network interfaces 214 (e.g., circuitry)for communicating between the processor 212 and other devices, thoseother devices possibly located across the network 205; (c) a memorydevice 216 (e.g., FLASH memory, a random access memory (RAM) device or aread-only memory (ROM) device for storing information (e.g.,instructions executed by processor 212 and data operated upon byprocessor 212 in response to such instructions)). In some embodiments,the information processing system 210 may also include a separatecomputer-readable medium 218 operably coupled to the processor 212 forstoring information and instructions as described further below.

In one embodiment, there is more than one network interface 214, so thatthe multiple network interfaces can be used to separately routemanagement, production, and other traffic. In one exemplary embodiment,an information processing system has a “management” interface at 1 GB/s,a “production” interface at 10 GB/s, and may have additional interfacesfor channel bonding, high availability, or performance. An informationprocessing device configured as a processing or routing node may alsohave an additional interface dedicated to public Internet traffic, andspecific circuitry or resources necessary to act as a VLAN trunk.

In some embodiments, the information processing system 210 may include aplurality of input/output devices 220 a-n which is operably coupled tothe processor 212, for inputting or outputting information, such as adisplay device 220 a, a print device 220 b, or other electroniccircuitry 220 c-n for performing other operations of the informationprocessing system 210 known in the art.

With reference to the computer-readable media, including both memorydevice 216 and secondary computer-readable medium 218, thecomputer-readable media and the processor 212 are structurally andfunctionally interrelated with one another as described below in furtherdetail, and information processing system of the illustrative embodimentis structurally and functionally interrelated with a respectivecomputer-readable medium similar to the manner in which the processor212 is structurally and functionally interrelated with thecomputer-readable media 216 and 218. As discussed above, thecomputer-readable media may be implemented using a hard disk drive, amemory device, and/or a variety of other computer-readable media knownin the art, and when including functional descriptive material, datastructures are created that define structural and functionalinterrelationships between such data structures and thecomputer-readable media (and other aspects of the system 200). Suchinterrelationships permit the data structures' functionality to berealized. For example, in one embodiment the processor 212 reads (e.g.,accesses or copies) such functional descriptive material from thenetwork interface 214, the computer-readable media 218 onto the memorydevice 216 of the information processing system 210, and the informationprocessing system 210 (more particularly, the processor 212) performsits operations, as described elsewhere herein, in response to suchmaterial stored in the memory device of the information processingsystem 210. In addition to reading such functional descriptive materialfrom the computer-readable medium 218, the processor 212 is capable ofreading such functional descriptive material from (or through) thenetwork 105. In one embodiment, the information processing system 210includes at least one type of computer-readable media that isnon-transitory. For explanatory purposes below, singular forms such as“computer-readable medium,” “memory,” and “disk” are used, but it isintended that these may refer to all or any portion of thecomputer-readable media available in or to a particular informationprocessing system 210, without limiting them to a specific location orimplementation.

The information processing system 210 includes a hypervisor 230. Thehypervisor 230 may be implemented in software, as a subsidiaryinformation processing system, or in a tailored electrical circuit or assoftware instructions to be used in conjunction with a processor tocreate a hardware-software combination that implements the specificfunctionality described herein. To the extent that software is used toimplement the hypervisor, it may include software that is stored on acomputer-readable medium, including the computer-readable medium 218.The hypervisor may be included logically “below” a host operatingsystem, as a host itself, as part of a larger host operating system, oras a program or process running “above” or “on top of” a host operatingsystem. Examples of hypervisors include Xenserver, KVM, VMware,Microsoft's Hyper-V, and emulation programs such as QEMU.

The hypervisor 230 includes the functionality to add, remove, and modifya number of logical containers 232 a-n associated with the hypervisor.Zero, one, or many of the logical containers 232 a-n contain associatedoperating environments 234 a-n. The logical containers 232 a-n canimplement various interfaces depending upon the desired characteristicsof the operating environment. In one embodiment, a logical container 232implements a hardware-like interface, such that the associated operatingenvironment 234 appears to be running on or within an informationprocessing system such as the information processing system 210. Forexample, one embodiment of a logical container 234 could implement aninterface resembling an x86, x86-64, ARM, or other computer instructionset with appropriate RAM, busses, disks, and network devices. Acorresponding operating environment 234 for this embodiment could be anoperating system such as Microsoft Windows, Linux, Linux-Android, or MacOS X. In another embodiment, a logical container 232 implements anoperating system-like interface, such that the associated operatingenvironment 234 appears to be running on or within an operating system.For example one embodiment of this type of logical container 232 couldappear to be a Microsoft Windows, Linux, or Mac OS X operating system.Another possible operating system includes an Android operating system,which includes significant runtime functionality on top of a lower-levelkernel. A corresponding operating environment 234 could enforceseparation between users and processes such that each process or groupof processes appeared to have sole access to the resources of theoperating system. In a third environment, a logical container 232implements a software-defined interface, such a language runtime orlogical process that the associated operating environment 234 can use torun and interact with its environment. For example one embodiment ofthis type of logical container 232 could appear to be a Java, Dalvik,Lua, Python, or other language virtual machine. A correspondingoperating environment 234 would use the built-in threading, processing,and code loading capabilities to load and run code. Adding, removing, ormodifying a logical container 232 may or may not also involve adding,removing, or modifying an associated operating environment 234. For easeof explanation below, these operating environments will be described interms of an embodiment as “Virtual Machines,” or “VMs,” but this issimply one implementation among the options listed above.

In one or more embodiments, a VM has one or more virtual networkinterfaces 236. How the virtual network interface is exposed to theoperating environment depends upon the implementation of the operatingenvironment. In an operating environment that mimics a hardwarecomputer, the virtual network interface 236 appears as one or morevirtual network interface cards. In an operating environment thatappears as an operating system, the virtual network interface 236appears as a virtual character device or socket. In an operatingenvironment that appears as a language runtime, the virtual networkinterface appears as a socket, queue, message service, or otherappropriate construct. The virtual network interfaces (VNIs) 236 may beassociated with a virtual switch (Vswitch) at either the hypervisor orcontainer level. The VNI 236 logically couples the operating environment234 to the network, and allows the VMs to send and receive networktraffic. In one embodiment, the physical network interface card 214 isalso coupled to one or more VMs through a Vswitch.

In one or more embodiments, each VM includes identification data for usenaming, interacting, or referring to the VM. This can include the MediaAccess Control (MAC) address, the Internet Protocol (IP) address, andone or more unambiguous names or identifiers.

In one or more embodiments, a “volume” is a detachable block storagedevice. In some embodiments, a particular volume can only be attached toone instance at a time, whereas in other embodiments a volume works likea Storage Area Network (SAN) so that it can be concurrently accessed bymultiple devices. Volumes can be attached to either a particularinformation processing device or a particular virtual machine, so theyare or appear to be local to that machine. Further, a volume attached toone information processing device or VM can be exported over the networkto share access with other instances using common file sharingprotocols. In other embodiments, there are areas of storage declared tobe “local storage.” Typically a local storage volume will be storagefrom the information processing device shared with or exposed to one ormore operating environments on the information processing device. Localstorage is guaranteed to exist only for the duration of the operatingenvironment; recreating the operating environment may or may not removeor erase any local storage associated with that operating environment.

Turning now to FIG. 3, a simple network operating environment 300 for acloud controller or cloud service is shown. The network operatingenvironment 300 includes multiple information processing systems 310a-n, each of which correspond to a single information processing system210 as described relative to FIG. 2, including a hypervisor 230, zero ormore logical containers 232 and zero or more operating environments 234.The information processing systems 310 a-n are connected via acommunication medium 312, typically implemented using a known networkprotocol such as Ethernet, Fibre Channel, Infiniband, or IEEE 1394. Forease of explanation, the network operating environment 300 will bereferred to as a “cluster,” “group,” or “zone” of operatingenvironments. The cluster may also include a cluster monitor 314 and anetwork routing element 316. The cluster monitor 314 and network routingelement 316 may be implemented as hardware, as software running onhardware, or may be implemented completely as software. In oneimplementation, one or both of the cluster monitor 314 or networkrouting element 316 is implemented in a logical container 232 using anoperating environment 234 as described above. In another embodiment, oneor both of the cluster monitor 314 or network routing element 316 isimplemented so that the cluster corresponds to a group of physicallyco-located information processing systems, such as in a rack, row, orgroup of physical machines.

The cluster monitor 314 provides an interface to the cluster in general,and provides a single point of contact allowing someone outside thesystem to query and control any one of the information processingsystems 310, the logical containers 232 and the operating environments234. In one embodiment, the cluster monitor also provides monitoring andreporting capabilities.

The network routing element 316 allows the information processingsystems 310, the logical containers 232 and the operating environments234 to be connected together in a network topology. The illustrated treetopology is only one possible topology; the information processingsystems and operating environments can be logically arrayed in a ring,in a star, in a graph, or in multiple logical arrangements through theuse of vLANs.

In one embodiment, the cluster also includes a cluster controller 318.The cluster controller is outside the cluster, and is used to store orprovide identifying information associated with the differentaddressable elements in the cluster—specifically the cluster generally(addressable as the cluster monitor 314), the cluster network router(addressable as the network routing element 316), each informationprocessing system 310, and with each information processing system theassociated logical containers 232 and operating environments 234.

The cluster controller 318 is outside the cluster, and is used to storeor provide identifying information associated with the differentaddressable elements in the cluster—specifically the cluster generally(addressable as the cluster monitor 314), the cluster network router(addressable as the network routing element 316), each informationprocessing system 310, and with each information processing system theassociated logical containers 232 and operating environments 234. In oneembodiment, the cluster controller 318 includes a registry of VMinformation 319. In a second embodiment, the registry 319 is associatedwith but not included in the cluster controller 318.

In one embodiment, the cluster also includes one or more instructionprocessors 320. In the embodiment shown, the instruction processor islocated in the hypervisor, but it is also contemplated to locate aninstruction processor within an active VM or at a cluster level, forexample in a piece of machinery associated with a rack or cluster. Inone embodiment, the instruction processor 320 is implemented in atailored electrical circuit or as software instructions to be used inconjunction with a physical or virtual processor to create ahardware-software combination that implements the specific functionalitydescribed herein. To the extent that one embodiment includescomputer-executable instructions, those instructions may includesoftware that is stored on a computer-readable medium. Further, one ormore embodiments have associated with them a buffer 322. The buffer 322can take the form of data structures, a memory, a computer-readablemedium, or an off-script-processor facility. For example, one embodimentuses a language runtime as an instruction processor 320. The languageruntime can be run directly on top of the hypervisor, as a process in anactive operating environment, or can be run from a low-power embeddedprocessor. In a second embodiment, the instruction processor 320 takesthe form of a series of interoperating but discrete components, some orall of which may be implemented as software programs. For example, inthis embodiment, an interoperating bash shell, gzip program, an rsyncprogram, and a cryptographic accelerator chip are all components thatmay be used in an instruction processor 320. In another embodiment, theinstruction processor 320 is a discrete component, using a small amountof flash and a low power processor, such as a low-power ARM processor.This hardware-based instruction processor can be embedded on a networkinterface card, built into the hardware of a rack, or provided as anadd-on to the physical chips associated with an information processingsystem 310. It is expected that in many embodiments, the instructionprocessor 320 will have an integrated battery and will be able to spendan extended period of time without drawing current. Various embodimentsalso contemplate the use of an embedded Linux or Linux-Androidenvironment.

Networking

Referring now to FIG. 4 a, a diagram of the network connectionsavailable to one embodiment of the system is shown. The network 400 isone embodiment of a virtual network 116 as discussed relative to FIG. 1,and is implemented on top of the internal network layer 114. Aparticular node is connected to the virtual network 400 through avirtual network interface 236 operating through physical networkinterface 214. The VLANs, VSwitches, VPNs, and other pieces of networkhardware (real or virtual) are may be network routing elements 316 ormay serve another function in the communications medium 312.

In one embodiment, the cloud computing system 110 uses both “fixed” IPsand “floating” IPs to address virtual machines. Fixed IPs are assignedto an instance on creation and stay the same until the instance isexplicitly terminated. Floating IPs are IP addresses that can bedynamically associated with an instance. A floating IP address can bedisassociated and associated with another instance at any time.

Different embodiments include various strategies for implementing andallocating fixed IPs, including “flat” mode, a “flat DHCP” mode, and a“VLAN DHCP” mode.

In one embodiment, fixed IP addresses are managed using a flat Mode. Inthis embodiment, an instance receives a fixed IP from a pool ofavailable IP addresses. All instances are attached to the same bridge bydefault. Other networking configuration instructions are placed into theinstance before it is booted or on boot.

In another embodiment, fixed IP addresses are managed using a flat DHCPmode. Flat DHCP mode is similar to the flat mode, in that all instancesare attached to the same bridge. Instances will attempt to bridge usingthe default Ethernet device or socket. Instead of allocation from afixed pool, a DHCP server listens on the bridge and instances receivetheir fixed IPs by doing a dhcpdiscover.

Turning now to a preferred embodiment using VLAN DHCP mode, there aretwo groups of off-local-network users, the private users 402 and thepublic internet users 404. To respond to communications from the privateusers 402 and the public users 404, the network 400 includes threenodes, network node 410, private node 420, and public node 430. Thenodes include one or more virtual machines or virtual devices, such asDNS/DHCP server 412 and virtual router VM 414 on network node 410, VPNVM 422 and private VM 424 on private node 420, and public VM 432 onpublic node 430.

In one embodiment, VLAN DHCP mode requires a switch that supportshost-managed VLAN tagging. In one embodiment, there is a VLAN 406 andbridge 416 for each project or group. In the illustrated embodiment,there is a VLAN associated with a particular project. The projectreceives a range of private IP addresses that are only accessible frominside the VLAN. and assigns an IP address from this range to privatenode 420, as well as to a VNI in the virtual devices in the VLAN. In oneembodiment, DHCP server 412 is running on a VM that receives a staticVLAN IP address at a known address, and virtual router VM 414, VPN VM422, private VM 424, and public VM 432 all receive private IP addressesupon request to the DHCP server running on the DHCP server VM. Inaddition, the DHCP server provides a public IP address to the virtualrouter VM 414 and optionally to the public VM 432. In a secondembodiment, the DHCP server 412 is running on or available from thevirtual router VM 414, and the public IP address of the virtual routerVM 414 is used as the DHCP address.

In an embodiment using VLAN DHCP mode, there is a private networksegment for each project's or group's instances that can be accessed viaa dedicated VPN connection from the Internet. As described below, eachVLAN project or group gets its own VLAN, network bridge, and subnet. Inone embodiment, subnets are specified by the network administrator, andassigned dynamically to a project or group when required. A DHCP Serveris started for each VLAN to pass out IP addresses to VM instances fromthe assigned subnet. All instances belonging to the VLAN project orgroup are bridged into the same VLAN. In this fashion, network trafficbetween VM instances belonging to the same VLAN is always open but thesystem can enforce isolation of network traffic between differentprojects by enforcing one VLAN per project.

As shown in FIG. 4 a, VLAN DHCP mode includes provisions for bothprivate and public access. For private access (shown by the arrows toand from the private users cloud 402), users create an access keypair(as described further below) for access to the virtual private networkthrough the gateway VPN VM 422. From the VPN VM 422, both the private VM424 and the public VM 432 are accessible via the private IP addressesvalid on the VLAN.

Public access is shown by the arrows to and from the public users cloud404. Communications that come in from the public users cloud arrive atthe virtual router VM 414 and are subject to network address translation(NAT) to access the public virtual machine via the bridge 416.Communications out from the private VM 424 are source NATted by thebridge 416 so that the external source appears to be the virtual routerVM 414. If the public VM 432 does not have an externally routableaddress, communications out from the public VM 432 may be source NATtedas well.

In one embodiment of VLAN DHCP mode, the second IP in each privatenetwork is reserved for the VPN VM instance 422. This gives a consistentIP to the instance so that forwarding rules can be more easily created.The network for each project is given a specific high-numbered port onthe public IP of the network node 410. This port is automaticallyforwarded to the appropriate VPN port on the VPN VM 422.

In one embodiment, each group or project has its own certificateauthority (CA) 423. The CA 423 is used to sign the certificate for theVPN VM 422, and is also passed to users on the private users cloud 402.When a certificate is revoked, a new Certificate Revocation List (CRL)is generated. The VPN VM 422 will block revoked users from connecting tothe VPN if they attempt to connect using a revoked certificate.

In a project VLAN organized similarly to the embodiment described above,the project has an independent RFC 1918 IP space; public IP via NAT; hasno default inbound network access without public NAT; has limited,controllable outbound network access; limited, controllable access toother project segments; and VPN access to instance and cloud APIs.Further, there is a DMZ segment for support services, allowing projectmetadata and reporting to be provided in a secure manner.

In one embodiment, VLANs are segregated using 802.1q VLAN tagging in theswitching layer, but other tagging schemes such as 802.1ad, MPLS, orframe tagging are also contemplated. Network hosts create VLAN-specificinterfaces and bridges as required.

In one embodiment, private VM 424 has per-VLAN interfaces and bridgescreated as required. These do not have IP addresses in the host toprotect host access. Access is provided via routing table entriescreated per project and instance to protect against IP/MAC addressspoofing and ARP poisoning.

FIG. 4 b is a flowchart showing the establishment of a VLAN for aproject according to one embodiment. The process 450 starts at step 451,when a VM instance for the project is requested. When running a VMinstance, a user needs to specify a project for the instances, and theapplicable security rules and security groups (as described herein) thatthe instance should join. At step 452, a cloud controller determines ifthis is the first instance to be created for the project. If this is thefirst, then the process proceeds to step 453. If the project alreadyexists, then the process moves to step 459. At step 453, a networkcontroller is identified to act as the network host for the project.This may involve creating a virtual network device and assigning it therole of network controller. In one embodiment, this is a virtual routerVM 414. At step 454, an unused VLAN id and unused subnet are identified.At step 455, the VLAN id and subnet are assigned to the project. At step456, DHCP server 412 and bridge 416 are instantiated and registered. Atstep 457, the VM instance request is examined to see if the request isfor a private VM 424 or public VM 432. If the request is for a privateVM, the process moves to step 458. Otherwise, the process moves to step460. At step 458, the VPN VM 422 is instantiated and allocated thesecond IP in the assigned subnet. At step 459, the subnet and a VLANhave already been assigned to the project. Accordingly, the requested VMis created and assigned and assigned a private IP within the project'ssubnet. At step 460, the routing rules in bridge 416 are updated toproperly NAT traffic to or from the requested VM.

Message Service

Between the various virtual machines and virtual devices, it may benecessary to have a reliable messaging infrastructure. In variousembodiments, a message queuing service is used for both local and remotecommunication so that there is no requirement that any of the servicesexist on the same physical machine. Various existing messaginginfrastructures are contemplated, including AMQP, ZeroMQ, STOMP andXMPP. Note that this messaging system may or may not be available foruser-addressable systems; in one preferred embodiment, there is aseparation between internal messaging services and any messagingservices associated with user data.

In one embodiment, the message service sits between various componentsand allows them to communicate in a loosely coupled fashion. This can beaccomplished using Remote Procedure Calls (RPC hereinafter) tocommunicate between components, built atop either direct messages and/oran underlying publish/subscribe infrastructure. In a typical embodiment,it is expected that both direct and topic-based exchanges are used. Thisallows for decoupling of the components, full asynchronouscommunications, and transparent balancing between equivalent components.In some embodiments, calls between different APIs can be supported overthe distributed system by providing an adapter class which takes care ofmarshalling and unmarshalling of messages into function calls.

In one embodiment, a cloud controller 120 (or the applicable cloudservice 130) creates two queues at initialization time, one that acceptsnode-specific messages and another that accepts generic messagesaddressed to any node of a particular type. This allows both specificnode control as well as orchestration of the cloud service withoutlimiting the particular implementation of a node. In an embodiment inwhich these message queues are bridged to an API, the API can act as aconsumer, server, or publisher.

Turning now to FIG. 5 a, one implementation of a message service 140 isshown at reference number 500. For simplicity of description, FIG. 5 ashows the message service 500 when a single instance 502 is deployed andshared in the cloud computing system 110, but the message service 500can be either centralized or fully distributed.

In one embodiment, the message service 500 keeps traffic associated withdifferent queues or routing keys separate, so that disparate servicescan use the message service without interfering with each other.Accordingly, the message queue service may be used to communicatemessages between network elements, between cloud services 130, betweencloud controllers 120, between network elements, or between any group ofsub-elements within the above. More than one message service 500 may beused, and a cloud service 130 may use its own message service asrequired.

For clarity of exposition, access to the message service 500 will bedescribed in terms of “Invokers” and “Workers,” but these labels arepurely expository and are not intended to convey a limitation onpurpose; in some embodiments, a single component (such as a VM) may actfirst as an Invoker, then as a Worker, the other way around, orsimultaneously in each role. An Invoker is a component that sendsmessages in the system via two operations: 1) an RPC (Remote ProcedureCall) directed message and ii) an RPC broadcast. A Worker is a componentthat receives messages from the message system and replies accordingly.

In one embodiment, there is a message server 505 including one or moreexchanges 510. In a second embodiment, the message system is“brokerless,” and one or more exchanges are located at each client. Theexchanges 510 act as internal message routing elements so thatcomponents interacting with the message service 500 can send and receivemessages. In one embodiment, these exchanges are subdivided further intoa topic exchange 510 a and a direct exchange 510 b. An exchange 510 is arouting structure or system that exists in a particular context. In acurrently preferred embodiment, multiple contexts can be included withina single message service with each one acting independently of theothers. In one embodiment, the type of exchange, such as a topicexchange 510 a vs. direct exchange 510 b determines the routing policy.In a second embodiment, the routing policy is determined via a series ofrouting rules evaluated by the exchange 510.

The direct exchange 510 a is a routing element created during or for RPCdirected message operations. In one embodiment, there are many instancesof a direct exchange 510 a that are created as needed for the messageservice 500. In a further embodiment, there is one direct exchange 510 acreated for each RPC directed message received by the system.

The topic exchange 510 a is a routing element created during or for RPCdirected broadcast operations. In one simple embodiment, every messagereceived by the topic exchange is received by every other connectedcomponent. In a second embodiment, the routing rule within a topicexchange is described as publish-subscribe, wherein different componentscan specify a discriminating function and only topics matching thediscriminator are passed along. In one embodiment, there are manyinstances of a topic exchange 510 b that are created as needed for themessage service 500. In one embodiment, there is one topic-basedexchange for every topic created in the cloud computing system. In asecond embodiment, there are a set number of topics that havepre-created and persistent topic exchanges 510 b.

Within one or more of the exchanges 510, it may be useful to have aqueue element 515. A queue 515 is a message stream; messages sent intothe stream are kept in the queue 515 until a consuming componentconnects to the queue and fetches the message. A queue 515 can be sharedor can be exclusive. In one embodiment, queues with the same topic areshared amongst Workers subscribed to that topic.

In a typical embodiment, a queue 515 will implement a FIFO policy formessages and ensure that they are delivered in the same order that theyare received. In other embodiments, however, a queue 515 may implementother policies, such as LIFO, a priority queue (highest-prioritymessages are delivered first), or age (oldest objects in the queue aredelivered first), or other configurable delivery policies. In otherembodiments, a queue 515 may or may not make any guarantees related tomessage delivery or message persistence.

In one embodiment, element 520 is a topic publisher. A topic publisher520 is created, instantiated, or awakened when an RPC directed messageor an RPC broadcast operation is executed; this object is instantiatedand used to push a message to the message system. Every publisherconnects always to the same topic-based exchange; its life-cycle islimited to the message delivery.

In one embodiment, element 530 is a direct consumer. A direct consumer530 is created, instantiated, or awakened if an RPC directed messageoperation is executed; this component is instantiated and used toreceive a response message from the queuing system. Every directconsumer 530 connects to a unique direct-based exchange via a uniqueexclusive queue, identified by a UUID or other unique name. Thelife-cycle of the direct consumer 530 is limited to the messagedelivery. In one embodiment, the exchange and queue identifiers areincluded the message sent by the topic publisher 520 for RPC directedmessage operations.

In one embodiment, elements 540 (elements 540 a and 540 b) are topicconsumers. In one embodiment, a topic consumer 540 is created,instantiated, or awakened at system start. In a second embodiment, atopic consumer 540 is created, instantiated, or awakened when a topic isregistered with the message system 500. In a third embodiment, a topicconsumer 540 is created, instantiated, or awakened at the same time thata Worker or Workers are instantiated and persists as long as theassociated Worker or Workers have not been destroyed. In thisembodiment, the topic consumer 540 is used to receive messages from thequeue and it invokes the appropriate action as defined by the Workerrole. A topic consumer 540 connects to the topic-based exchange eithervia a shared queue or via a unique exclusive queue. In one embodiment,every Worker has two associated topic consumers 540, one that isaddressed only during an RPC broadcast operations (and it connects to ashared queue whose exchange key is defined by the topic) and the otherthat is addressed only during an RPC directed message operations,connected to a unique queue whose with the exchange key is defined bythe topic and the host.

In one embodiment, element 550 is a direct publisher. In one embodiment,a direct publisher 550 is created, instantiated, or awakened for RPCdirected message operations and it is instantiated to return the messagerequired by the request/response operation. The object connects to adirect-based exchange whose identity is dictated by the incomingmessage.

Turning now to FIG. 5 b, one embodiment of the process of sending an RPCdirected message is shown relative to the elements of the message system500 as described relative to FIG. 5 a. All elements are as describedabove relative to FIG. 5 a unless described otherwise. At step 560, atopic publisher 520 is instantiated. At step 561, the topic publisher520 sends a message to an exchange 510 b. At step 562, a direct consumer530 is instantiated to wait for the response message. At step 563, themessage is dispatched by the exchange 510 b. At step 564, the message isfetched by the topic consumer 540 dictated by the routing key (either bytopic or by topic and host). At step 565, the message is passed to aWorker associated with the topic consumer 540. If needed, at step 566, adirect publisher 550 is instantiated to send a response message via themessage system 500. At step 567, the direct publisher 540 sends amessage to an exchange 510 a. At step 568, the response message isdispatched by the exchange 510 a. At step 569, the response message isfetched by the direct consumer 530 instantiated to receive the responseand dictated by the routing key. At step 570, the message response ispassed to the Invoker.

Turning now to FIG. 5 c, one embodiment of the process of sending an RPCbroadcast message is shown relative to the elements of the messagesystem 500 as described relative to FIG. 5 a. All elements are asdescribed above relative to FIG. 5 a unless described otherwise. At step580, a topic publisher 520 is instantiated. At step 581, the topicpublisher 520 sends a message to an exchange 510 b. At step 582, themessage is dispatched by the exchange 510 b. At step 583, the message isfetched by a topic consumer 540 dictated by the routing key (either bytopic or by topic and host). At step 584, the message is passed to aWorker associated with the topic consumer 540.

In some embodiments, a response to an RPC broadcast message can berequested. In that case, the process follows the steps outlined relativeto FIG. 5 b to return a response to the Invoker.

Rule Engine

Because many aspects of the cloud computing system do not allow directaccess to the underlying hardware or services, many aspects of the cloudcomputing system are handled declaratively, through rule-basedcomputing. Rule-based computing organizes statements into a data modelthat can be used for deduction, rewriting, and other inferential ortransformational tasks. The data model can then be used to representsome problem domain and reason about the objects in that domain and therelations between them. In one embodiment, one or more controllers orservices have an associated rule processor that performs rule-baseddeduction, inference, and reasoning.

Rule Engines can be implemented similarly to instruction processors asdescribed relative to FIG. 3, and may be implemented as a sub-module ofa instruction processor where needed. In other embodiments, Rule Enginescan be implemented as discrete components, for example as a tailoredelectrical circuit or as software instructions to be used in conjunctionwith a hardware processor to create a hardware-software combination thatimplements the specific functionality described herein. To the extentthat one embodiment includes computer-executable instructions, thoseinstructions may include software that is stored on a computer-readablemedium. Further, one or more embodiments have associated with them abuffer. The buffer can take the form of data structures, a memory, acomputer-readable medium, or an off-rule-engine facility. For example,one embodiment uses a language runtime as a rule engine, running as adiscrete operating environment, as a process in an active operatingenvironment, or can be run from a low-power embedded processor. In asecond embodiment, the rule engine takes the form of a series ofinteroperating but discrete components, some or all of which may beimplemented as software programs. In another embodiment, the rule engineis a discrete component, using a small amount of flash and a low powerprocessor, such as a low-power ARM processor.

Security and Access Control

One subset of rule-based systems is role-based computing systems. Arole-based computing system is a system in which identities andresources are managed by aggregating them into “roles” based on jobfunctions, physical location, legal controls, and other criteria. Theseroles can be used to model organizational structures, manage assets, ororganize data. By arranging roles and the associated rules into graphsor hierarchies, these roles can be used to reason about and managevarious resources.

In one application, role-based strategies have been used to form asecurity model called Role-Based Access Control (RBAC). RBAC associatesspecial rules, called “permissions,” with roles; each role is grantedonly the minimum permissions necessary for the performance of thefunctions associated with that role. Identities are assigned to roles,giving the users and other entities the permissions necessary toaccomplish job functions. RBAC has been formalized mathematically byNIST and accepted as a standard by ANSI. American National Standard359-2004 is the information technology industry consensus standard forRBAC, and is incorporated herein by reference in its entirety.

Because the cloud computing systems are designed to be multi-tenant, itis necessary to include limits and security in the basic architecture ofthe system. In one preferred embodiment, this is done through rulesdeclaring the existence of users, resources, projects, and groups.Rule-based access controls govern the use and interactions of theselogical entities.

In a preferred embodiment, a user is defined as an entity that will actin one or more roles. A user is typically associated with an internal orexternal entity that will interact with the cloud computing system insome respect. A user can have multiple roles simultaneously. In oneembodiment of the system, a user's roles define which API commands thatuser can perform.

In a preferred embodiment, a resource is defined as some object to whichaccess is restricted. In various embodiments, resources can includenetwork or user access to a virtual machine or virtual device, theability to use the computational abilities of a device, access tostorage, an amount of storage, API access, ability to configure anetwork, ability to access a network, network bandwidth, network speed,network latency, ability to access or set authentication rules, abilityto access or set rules regarding resources, etc. In general, any itemwhich may be restricted or metered is modeled as a resource.

In one embodiment, resources may have quotas associated with them. Aquota is a rule limiting the use or access to a resource. A quota can beplaced on a per-project level, a per-role level, a per-user level, or aper-group level. In one embodiment, quotas can be applied to the numberof volumes which can be created, the total size of all volumes within aproject or group, the number of instances which can be launched, bothtotal and per instance type, the number of processor cores which can beallocated, and publicly accessible IP addresses. Other restrictions arealso contemplated as described herein.

In a preferred embodiment, a project is defined as a flexibleassociation of users, acting in certain roles, that will define andaccess various resources. A project is typically defined by anadministrative user according to varying demands. There may be templatesfor certain types of projects, but a project is a logical groupingcreated for administrative purposes and may or may not bear a necessaryrelation to anything outside the project. In a preferred embodiment,arbitrary roles can be defined relating to one or more particularprojects only.

In a preferred embodiment, a group is defined as a logical associationof some other defined entity. There may be groups of users, groups ofresources, groups of projects, groups of quotas, or groups which containmultiple different types of defined entities. For example, in oneembodiment, a group “development” is defined. The development group mayinclude a group of users with the tag “developers” and a group ofvirtual machine resources (“developer machines”). These may be connectedto a developer-only virtual network (“devnet”). The development groupmay have a number of ongoing development projects, each with anassociated “manager” role. There may be per-user quotas on storage and agroup-wide quota on the total monthly bill associated with alldevelopment resources.

The applicable set of rules, roles, and quotas is based upon context. Inone embodiment, there are global roles, user-specific roles,project-specific roles, and group-specific roles. In one embodiment, auser's actual permissions in a particular project are the intersectionof the global roles, user-specific roles, project-specific roles, andgroup-specific roles associated with that user, as well as any rulesassociated with project or group resources possibly affected by theuser.

In one preferred embodiment, authentication of a user is performedthrough public/private encryption, with keys used to authenticateparticular users, or in some cases, particular resources such asparticular machines. A user or machine may have multiple keypairsassociated with different roles, projects, groups, or permissions. Forexample, a different key may be needed for general authentication andfor project access. In one such embodiment, a user is identified withinthe system by the possession and use of one or more cryptographic keys,such as an access and secret key. A user's access key needs to beincluded in a request, and the request must be signed with the secretkey. Upon receipt of API requests, the rules engine verifies thesignature and executes commands on behalf of the user.

Some resources, such as virtual machine images, can be shared by manyusers. Accordingly, it can be impractical or insecure to include privatecryptographic information in association with a shared resource. In oneembodiment, the system supports providing public keys to resourcesdynamically. In one exemplary embodiment, a public key, such as an SSHkey, is injected into a VM instance before it is booted. This allows auser to login to the instances securely, without sharing private keyinformation and compromising security. Other shared resources thatrequire per-instance authentication are handled similarly.

In one embodiment, a rule processor is also used to attach and evaluaterule-based restrictions on non-user entities within the system. In thisembodiment, a “Cloud Security Group” (or just “security group”) is anamed collection of access rules that apply to one or more non-userentities. Typically these will include network access rules, such asfirewall policies, applicable to a resource, but the rules may apply toany resource, project, or group. For example, in one embodiment asecurity group specifies which incoming network traffic should bedelivered to all VM instances in the group, all other incoming trafficbeing discarded. Users with the appropriate permissions (as defined bytheir roles) can modify rules for a group. New rules are automaticallyenforced for all running instances and instances launched from then on.

When launching VM instances, a project or group administrator specifieswhich security groups it wants the VM to join. If the directive to jointhe groups has been given by an administrator with sufficientpermissions, newly launched VMs will become a member of the specifiedsecurity groups when they are launched. In one embodiment, an instanceis assigned to a “default” group if no groups are specified. In afurther embodiment, the default group allows all network traffic fromother members of this group and discards traffic from other IP addressesand groups. The rules associated with the default group can be modifiedby users with roles having the appropriate permissions.

In some embodiments, a security group is similar to a role for anon-user, extending RBAC to projects, groups, and resources. Forexample, one rule in a security group can stipulate that servers withthe “webapp” role must be able to connect to servers with the “database”role on port 3306. In some embodiments, an instance can be launched withmembership of multiple security groups—similar to a server with multipleroles. Security groups are not necessarily limited, and can be equallyexpressive as any other type of RBAC security. In one preferredembodiment, all rules in security groups are ACCEPT rules, making themeasily composable.

In one embodiment, each rule in a security group must specify the sourceof packets to be allowed. This can be specified using CIDR notation(such as 10.22.0.0/16, representing a private subnet in the 10.22 IPspace, or 0.0.0.0/0 representing the entire Internet) or anothersecurity group. The creation of rules with other security groupsspecified as sources helps deal with the elastic nature of cloudcomputing; instances are impermanent and IP addresses frequently change.In this embodiment, security groups can be maintained dynamicallywithout having to adjust actual IP addresses.

In one embodiment, the APIs, RBAC-based authentication system, andvarious specific roles are used to provide a USeAuthentication-compatible federated authentication system to achieveaccess controls and limits based on traditional operational roles. In afurther embodiment, the implementation of auditing APIs provides thenecessary environment to receive a certification under FIPS 199 Moderateclassification for a hybrid cloud environment.

Typical implementations of US eAuthentication-compatible systems arestructured as a Federated LDAP user store, back-ending to a SAML PolicyController. The SAML Policy Controller maps access requests or accesspaths, such as requests to particular URLs, to a Policy Agent in frontof an eAuth-secured application. In a preferred embodiment, theapplication-specific account information is stored either in extendedschema on the LDAP server itself, via the use of a translucent LDAPproxy, or in an independent datastore keyed off of the UID provided viaSAML assertion.

As described above, in one embodiment API calls are secured via accessand secret keys, which are used to sign API calls, along withtraditional timestamps to prevent replay attacks. The APIs can belogically grouped into sets that align with the following typical roles:

-   -   Base User    -   System Administrator    -   Developer    -   Network Administrator    -   Project Administrator    -   Group Administrator    -   Cloud Administrator    -   Security    -   End-user/Third-party User

In one currently preferred embodiment, System Administrators andDevelopers have the same permissions, Project and Group Administratorshave the same permissions, and Cloud Administrators and Security havethe same permissions. The End-user or Third-party User is optional andexternal, and may not have access to protected resources, includingAPIs. Additional granularity of permissions is possible by separatingthese roles. In various other embodiments, the RBAC security systemdescribed above is extended with SAML Token passing. The SAML token isadded to the API calls, and the SAML UID is added to the instancemetadata, providing end-to-end auditability of ownership andresponsibility.

In an embodiment using the roles above, APIs can be grouped according torole. Any authenticated user may:

-   -   Describe Instances    -   Describe Images    -   Describe Volumes    -   Describe Keypairs    -   Create Keypair    -   Delete Keypair    -   Create, Upload, Delete Buckets and Keys        System Administrators, Developers, Project Administrators, and        Group Administrators may:    -   Create, Attach, Delete Volume (Block Store)    -   Launch, Reboot, Terminate Instance    -   Register/Unregister Machine Image (project-wide)    -   Request or Review Audit Scans        Project or Group Administrators may:    -   Add and remove other users    -   Set roles    -   Manage groups        Network Administrators may:    -   Change Machine Image properties (public/private)    -   Change Firewall Rules    -   Define Cloud Security Groups    -   Allocate, Associate, Deassociate Public IP addresses

In this embodiment, Cloud Administrators and Security personnel wouldhave all permissions. In particular, access to the audit subsystem wouldbe restricted. Audit queries may spawn long-running processes, consumingresources. Further, detailed system information is a systemvulnerability, so proper restriction of audit resources and resultswould be restricted by role.

In an embodiment as described above, APIs are extended with threeadditional type declarations, mapping to the “Confidentiality,Integrity, Availability” (“C.I.A.”) classifications of FIPS 199. Theseadditional parameters would also apply to creation of block storagevolumes and creation of object storage “buckets.” C.I.A. classificationson a bucket would be inherited by the keys within the bucket.Establishing declarative semantics for individual API calls allows thecloud environment to seamlessly proxy API calls to external, third-partyvendors when the requested C.I.A. levels match.

In one embodiment, a hybrid or multi-vendor cloud uses the VLAN DHCPnetworking architecture described relative to FIG. 4 and the RBACcontrols to manage and secure inter-cluster networking. In this way thehybrid cloud environment provides dedicated, potentially co-locatedphysical hardware with a network interconnect to the project or users'cloud virtual network.

In one embodiment, the interconnect is a bridged VPN connection. In oneembodiment, there is a VPN server at each side of the interconnect witha unique shared certificate. A security group is created specifying theaccess at each end of the bridged connection. In a second embodiment,the interconnect VPN implements audit controls so that the connectionsbetween each side of the bridged connection can be queried andcontrolled. Network discovery protocols (ARP, CDP) can be used toprovide information directly, and existing protocols (SNMP locationdata, DNS LOC records) overloaded to provide audit information.

In the disclosure that follows, the information processing devices asdescribed relative to FIG. 2 and the clusters as described relative toFIG. 3 are used as underlying infrastructure to build and administervarious cloud services. Except where noted specifically, either a singleinformation processing device or a cluster can be used interchangeablyto implement a single “node,” “service,” or “controller.” Where aplurality of resources are described, such as a plurality of storagenodes or a plurality of compute nodes, the plurality of resources can beimplemented as a plurality of information processing devices, as aone-to-one relationship of information processing devices, logicalcontainers, and operating environments, or in an M×N relationship ofinformation processing devices to logical containers and operatingenvironments.

Various aspects of the services implemented in the cloud computingsystem may be referred to as “virtual machines” or “virtual devices”; asdescribed above, those refer to a particular logical container andoperating environment, configured to perform the service described. Theterm “instance” is sometimes used to refer to a particular virtualmachine running inside the cloud computing system. An “instance type”describes the compute, memory and storage capacity of particular VMinstances.

Within the architecture described above, various services are provided,and different capabilities can be included through a plug-inarchitecture. Although specific services and plugins are detailed below,these disclosures are intended to be representative of the services andplugins available for integration across the entire cloud computingsystem 110.

Turning now to FIG. 6, an IaaS-style computational cloud service (a“compute” service) is shown at 600 according to one embodiment. This isone embodiment of a cloud controller 120 with associated cloud service130 as described relative to FIG. 1. Except as described relative tospecific embodiments, the existence of a compute service does notrequire or prohibit the existence of other portions of the cloudcomputing system 110 nor does it require or prohibit the existence ofother cloud controllers 120 with other respective services 130.

To the extent that some components described relative to the computeservice 600 are similar to components of the larger cloud computingsystem 110, those components may be shared between the cloud computingsystem 110 and the compute service 600, or they may be completelyseparate. Further, to the extend that “controllers,” “nodes,” “servers,”“managers,” “VMs,” or similar terms are described relative to thecompute service 600, those can be understood to comprise any of a singleinformation processing device 210 as described relative to FIG. 2,multiple information processing devices 210, a single VM as describedrelative to FIG. 2, a group or cluster of VMs or information processingdevices as described relative to FIG. 3. These may run on a singlemachine or a group of machines, but logically work together to providethe described function within the system.

In one embodiment, compute service 600 includes an API Server 610, aCompute Controller 620, an Auth Manager 630, an Object Store 640, aVolume Controller 650, a Network Controller 660, and a Compute Manager670. These components are coupled by a communications network of thetype previously described. In one embodiment, communications betweenvarious components are message-oriented, using HTTP or a messagingprotocol such as AMQP, ZeroMQ, or STOMP.

Although various components are described as “calling” each other or“sending” data or messages, one embodiment makes the communications orcalls between components asynchronous with callbacks that get triggeredwhen responses are received. This allows the system to be architected ina “shared-nothing” fashion. To achieve the shared-nothing property withmultiple copies of the same component, compute service 600 furtherincludes distributed data store 690. Global state for compute service600 is written into this store using atomic transactions when required.Requests for system state are read out of this store. In someembodiments, results are cached within controllers for short periods oftime to improve performance. In various embodiments, the distributeddata store 690 can be the same as, or share the same implementation asObject Store 640.

In one embodiment, the API server 610 includes external API endpoints612. In one embodiment, the external API endpoints 612 are provided overan RPC-style system, such as CORBA, DCE/COM, SOAP, or XML-RPC. Thesefollow the calling structure and conventions defined in their respectivestandards. In another embodiment, the external API endpoints 612 arebasic HTTP web services following a REST pattern and identifiable viaURL. Requests to read a value from a resource are mapped to HTTP GETs,requests to create resources are mapped to HTTP PUTs, requests to updatevalues associated with a resource are mapped to HTTP POSTs, and requeststo delete resources are mapped to HTTP DELETEs. In some embodiments,other REST-style verbs are also available, such as the ones associatedwith WebDay. In a third embodiment, the API endpoints 612 are providedvia internal function calls, IPC, or a shared memory mechanism.Regardless of how the API is presented, the external API endpoints 612are used to handle authentication, authorization, and basic command andcontrol functions using various API interfaces. In one embodiment, thesame functionality is available via multiple APIs, including APIsassociated with other cloud computing systems. This enables APIcompatibility with multiple existing tool sets created for interactionwith offerings from other vendors.

The Compute Controller 620 coordinates the interaction of the variousparts of the compute service 600. In one embodiment, the variousinternal services that work together to provide the compute service 600,are internally decoupled by adopting a service-oriented architecture(SOA). The Compute Controller 620 serves as an internal API server,allowing the various internal controllers, managers, and othercomponents to request and consume services from the other components. Inone embodiment, all messages pass through the Compute Controller 620. Ina second embodiment, the Compute Controller 620 brings up services andadvertises service availability, but requests and responses go directlybetween the components making and serving the request. In a thirdembodiment, there is a hybrid model in which some services are requestedthrough the Compute Controller 620, but the responses are provideddirectly from one component to another.

In one embodiment, communication to and from the Compute Controller 620is mediated via one or more internal API endpoints 622, provided in asimilar fashion to those discussed above. The internal API endpoints 622differ from the external API endpoints 612 in that the internal APIendpoints 622 advertise services only available within the overallcompute service 600, whereas the external API endpoints 612 advertiseservices available outside the compute service 600. There may be one ormore internal APIs 622 that correspond to external APIs 612, but it isexpected that there will be a greater number and variety of internal APIcalls available from the Compute Controller 620.

In one embodiment, the Compute Controller 620 includes an instructionprocessor 624 for receiving and processing instructions associated withdirecting the compute service 600. For example, in one embodiment,responding to an API call involves making a series of coordinatedinternal API calls to the various services available within the computeservice 600, and conditioning later API calls on the outcome or resultsof earlier API calls. The instruction processor 624 is the componentwithin the Compute Controller 620 responsible for marshalling arguments,calling services, and making conditional decisions to respondappropriately to API calls.

In one embodiment, the instruction processor 624 is implemented asdescribed above relative to FIG. 3, specifically as a tailoredelectrical circuit or as software instructions to be used in conjunctionwith a hardware processor to create a hardware-software combination thatimplements the specific functionality described herein. To the extentthat one embodiment includes computer-executable instructions, thoseinstructions may include software that is stored on a computer-readablemedium. Further, one or more embodiments have associated with them abuffer. The buffer can take the form of data structures, a memory, acomputer-readable medium, or an off-script-processor facility. Forexample, one embodiment uses a language runtime as an instructionprocessor 624, running as a discrete operating environment, as a processin an active operating environment, or can be run from a low-powerembedded processor. In a second embodiment, the instruction processor624 takes the form of a series of interoperating but discretecomponents, some or all of which may be implemented as softwareprograms. In another embodiment, the instruction processor 624 is adiscrete component, using a small amount of flash and a low powerprocessor, such as a low-power ARM processor. In a further embodiment,the instruction processor includes a rule engine as a submodule asdescribed herein.

In one embodiment, the Compute Controller 620 includes a message queueas provided by message service 626. In accordance with theservice-oriented architecture described above, the various functionswithin the compute service 600 are isolated into discrete internalservices that communicate with each other by passing data in awell-defined, shared format, or by coordinating an activity between twoor more services. In one embodiment, this is done using a message queueas provided by message service 626. The message service 626 brokers theinteractions between the various services inside and outside the ComputeService 600.

In one embodiment, the message service 626 is implemented similarly tothe message service described relative to FIGS. 5 a-5 c. The messageservice 626 may use the message service 140 directly, with a set ofunique exchanges, or may use a similarly configured but separateservice.

The Auth Manager 630 provides services for authenticating and managinguser, account, role, project, group, quota, and security groupinformation for the compute service 600. In a first embodiment, everycall is necessarily associated with an authenticated and authorizedentity within the system, and so is or can be checked before any actionis taken. In another embodiment, internal messages are assumed to beauthorized, but all messages originating from outside the service aresuspect. In this embodiment, the Auth Manager checks the keys providedassociated with each call received over external API endpoints 612 andterminates and/or logs any call that appears to come from anunauthenticated or unauthorized source. In a third embodiment, the AuthManager 630 is also used for providing resource-specific informationsuch as security groups, but the internal API calls for that informationare assumed to be authorized. External calls are still checked forproper authentication and authorization. Other schemes forauthentication and authorization can be implemented by flagging certainAPI calls as needing verification by the Auth Manager 630, and others asneeding no verification.

In one embodiment, external communication to and from the Auth Manager630 is mediated via one or more authentication and authorization APIendpoints 632, provided in a similar fashion to those discussed above.The authentication and authorization API endpoints 632 differ from theexternal API endpoints 612 in that the authentication and authorizationAPI endpoints 632 are only used for managing users, resources, projects,groups, and rules associated with those entities, such as securitygroups, RBAC roles, etc. In another embodiment, the authentication andauthorization API endpoints 632 are provided as a subset of external APIendpoints 612.

In one embodiment, the Auth Manager 630 includes a rules processor 634for processing the rules associated with the different portions of thecompute service 600. In one embodiment, this is implemented in a similarfashion to the instruction processor 624 described above.

The Object Store 640 provides redundant, scalable object storagecapacity for arbitrary data used by other portions of the computeservice 600. At its simplest, the Object Store 640 can be implementedone or more block devices exported over the network. In a secondembodiment, the Object Store 640 is implemented as a structured, andpossibly distributed data organization system. Examples includerelational database systems—both standalone and clustered—as well asnon-relational structured data storage systems like MongoDB, ApacheCassandra, or Redis. In a third embodiment, the Object Store 640 isimplemented as a redundant, eventually consistent, fully distributeddata storage service.

In one embodiment, external communication to and from the Object Store640 is mediated via one or more object storage API endpoints 642,provided in a similar fashion to those discussed above. In oneembodiment, the object storage API endpoints 642 are internal APIs only.In a second embodiment, the Object Store 640 is provided by a separatecloud service 130, so the “internal” API used for compute service 600 isthe same as the external API provided by the object storage serviceitself.

In one embodiment, the Object Store 640 includes an Image Service 644.The Image Service 644 is a lookup and retrieval system for virtualmachine images. In one embodiment, various virtual machine images can beassociated with a unique project, group, user, or name and stored in theObject Store 640 under an appropriate key. In this fashion multipledifferent virtual machine image files can be provided andprogrammatically loaded by the compute service 600.

The Volume Controller 650 coordinates the provision of block devices foruse and attachment to virtual machines. In one embodiment, the VolumeController 650 includes Volume Workers 652. The Volume Workers 652 areimplemented as unique virtual machines, processes, or threads of controlthat interact with one or more backend volume providers 654 to create,update, delete, manage, and attach one or more volumes 656 to arequesting VM.

In a first embodiment, the Volume Controller 650 is implemented using aSAN that provides a sharable, network-exported block device that isavailable to one or more VMs, using a network block protocol such asiSCSI. In this embodiment, the Volume Workers 652 interact with the SANto manage and iSCSI storage to manage LVM-based instance volumes, storedon one or more smart disks or independent processing devices that act asvolume providers 654 using their embedded storage 656. In a secondembodiment, disk volumes 656 are stored in the Object Store 640 as imagefiles under appropriate keys. The Volume Controller 650 interacts withthe Object Store 640 to retrieve a disk volume 656 and place it withinan appropriate logical container on the same information processingsystem 240 that contains the requesting VM. An instruction processingmodule acting in concert with the instruction processor and hypervisoron the information processing system 240 acts as the volume provider654, managing, mounting, and unmounting the volume 656 on the requestingVM. In a further embodiment, the same volume 656 may be mounted on twoor more VMs, and a block-level replication facility may be used tosynchronize changes that occur in multiple places. In a thirdembodiment, the Volume Controller 650 acts as a block-device proxy forthe Object Store 640, and directly exports a view of one or moreportions of the Object Store 640 as a volume. In this embodiment, thevolumes are simply views onto portions of the Object Store 640, and theVolume Workers 654 are part of the internal implementation of the ObjectStore 640.

In one embodiment, the Network Controller 660 manages the networkingresources for VM hosts managed by the compute manager 670. Messagesreceived by Network Controller 660 are interpreted and acted upon tocreate, update, and manage network resources for compute nodes withinthe compute service, such as allocating fixed IP addresses, configuringVLANs for projects or groups, or configuring networks for compute nodes.

In one embodiment, the Network Controller 660 is implemented similarlyto the network controller described relative to FIGS. 4 a and 4 b. Thenetwork controller 660 may use a shared cloud controller directly, witha set of unique addresses, identifiers, and routing rules, or may use asimilarly configured but separate service.

In one embodiment, the Compute Manager 670 manages computing instancesfor use by API users using the compute service 600. In one embodiment,the Compute Manager 670 is coupled to a plurality of resource pools 672,each of which includes one or more compute nodes 674. Each compute node674 is a virtual machine management system as described relative to FIG.3 and includes a compute worker 676, a module working in conjunctionwith the hypervisor and instruction processor to create, administer, anddestroy multiple user- or system-defined logical containers andoperating environments—VMs—according to requests received through theAPI. In various embodiments, the pools of compute nodes may be organizedinto clusters, such as clusters 676 a and 676 b. In one embodiment, eachresource pool 672 is physically located in one or more data centers inone or more different locations. In another embodiment, resource poolshave different physical or software resources, such as differentavailable hardware, higher-throughput network connections, or lowerlatency to a particular location.

In one embodiment, the Compute Manager 670 allocates VM images toparticular compute nodes 674 via a Scheduler 678. The Scheduler 678 is amatching service; requests for the creation of new VM instances come inand the most applicable Compute nodes 674 are selected from the pool ofpotential candidates. In one embodiment, the Scheduler 678 selects acompute node 674 using a random algorithm. Because the node is chosenrandomly, the load on any particular node tends to be non-coupled andthe load across all resource pools tends to stay relatively even.

In a second embodiment, a smart scheduler 678 is used. A smart scheduleranalyzes the capabilities associated with a particular resource pool 672and its component services to make informed decisions on where a newinstance should be created. When making this decision it consults notonly all the Compute nodes across the resource pools 672 until the idealhost is found.

In a third embodiment, a distributed scheduler 678 is used. Adistributed scheduler is designed to coordinate the creation ofinstances across multiple compute services 600. Not only does thedistributed scheduler 678 analyze the capabilities associated with theresource pools 672 available to the current compute service 600, it alsorecursively consults the schedulers of any linked compute services untilthe ideal host is found.

In one embodiment, either the smart scheduler or the distributedscheduler is implemented using a rules engine 679 (not shown) and aseries of associated rules regarding costs and weights associated withdesired compute node characteristics. When deciding where to place anInstance, rules engine 679 compares a Weighted Cost for each node. Inone embodiment, the Weighting is just the sum of the total Costs. In asecond embodiment, a Weighting is calculated using a exponential orpolynomial algorithm. In the simplest embodiment, costs are nothing morethan integers along a fixed scale, although costs can also berepresented by floating point numbers, vectors, or matrices. Costs arecomputed by looking at the various Capabilities of the available noderelative to the specifications of the Instance being requested. Thecosts are calculated so that a “good” match has lower cost than a “bad”match, where the relative goodness of a match is determined by howclosely the available resources match the requested specifications.

In one embodiment, specifications can be hierarchical, and can includeboth hard and soft constraints. A hard constraint is a constraint is aconstraint that cannot be violated and have an acceptable response. Thiscan be implemented by having hard constraints be modeled asinfinite-cost requirements. A soft constraint is a constraint that ispreferable, but not required. Different soft constraints can havedifferent weights, so that fulfilling one soft constraint may be morecost-effective than another. Further, constraints can take on a range ofvalues, where a good match can be found where the available resource isclose, but not identical, to the requested specification. Constraintsmay also be conditional, such that constraint A is a hard constraint orhigh-cost constraint if Constraint B is also fulfilled, but can below-cost if Constraint C is fulfilled.

As implemented in one embodiment, the constraints are implemented as aseries of rules with associated cost functions. These rules can beabstract, such as preferring nodes that don't already have an existinginstance from the same project or group. Other constraints (hard orsoft), may include: a node with available GPU hardware; a node with anavailable network connection over 100 Mbps; a node that can run Windowsinstances; a node in a particular geographic location, etc.

When evaluating the cost to place a VM instance on a particular node,the constraints are computed to select the group of possible nodes, andthen a weight is computed for each available node and for each requestedinstance. This allows large requests to have dynamic weighting; if 1000instances are requested, the consumed resources on each node are“virtually” depleted so the Cost can change accordingly.

Turning now to FIG. 7, a diagram showing one embodiment of the processof instantiating, launching and authenticating a VM instance is shown asdiagram 700. In one embodiment, this corresponds to steps 458 and/or 459in FIG. 4 b. Although the implementation of the image instantiating andlaunching process will be shown in a manner consistent with theembodiment of the compute service 600 as shown relative to FIG. 6, theprocess is not limited to the specific functions or elements shown inFIG. 6. For clarity of explanation, internal details not relevant todiagram 700 have been removed from the diagram relative to FIG. 6.Further, while some requests and responses are shown in terms of directcomponent-to-component messages, in at least one embodiment the messagesare sent via a message service, such as message service 626 as describedrelative to FIG. 6.

Beginning at time 701, Auth Manager 630 receives a request to setupdefault permissions for controlling identity-based authentication. Inone embodiment, these permissions are generic to all identities. Inanother embodiment, the permissions apply to a single identity, such asa single MAC address. In another embodiment, the permissions apply to arange of identities, such as a range of MAC addresses. In oneembodiment, the permissions define the type of access that a particularidentity has to a certain resource. For example, the permissions maystate that MAC address 00-B0-D0-86-BB-F7 has read/write access to aconfiguration resource. In another embodiment, the permissions comprisea whitelist of identities that can access the resource. In anotherembodiment, the permissions comprise a blacklist of identities that arenot permitted to access the resource. In one embodiment, the request tosetup the default permissions is received via an API. In anotherembodiment, the request is received through a configuration tool such asa user interface.

In another embodiment, the permissions functionality is implementedaccording to the Role-Based Access Control (RBAC) security modeldiscussed previously. In such an embodiment, an identity or group ofidentities are assigned a role, and the role is granted the minimumpermissions necessary to perform the functions of the role. For example,a VM instance could be assigned the role of “Consumer.” An owner of aparticular resource may want VM's with the consumer role to be able toread from, but not write to the resource. The owner could configure thepermissions for the “Consumer” role to allow read-only access, and thusavoid having to configure individual entries for each identity. This isuseful since often the resource owner will not be aware of allidentities that will ultimately access the resource.

At time 702, the API Server 610 receives a request to create and run aVM instance with the appropriate arguments. In one embodiment, this isdone by using a command-line tool that issues arguments to the APIserver 610. In a second embodiment, this is done by sending a message tothe API Server 610. In one embodiment, the API to create and run the VMinstance includes arguments specifying a VM type, a VM image, andcontrol arguments. In one embodiment, the request also includesrequester information. In another embodiment, the request is signedand/or encrypted for security and privacy.

At time 704, API server 610 accepts the message, examines it for APIcompliance, and sends a message to Compute Controller 620, including theinformation needed to service the request. In the depicted embodiment,the information includes a user identification that identifies therequesting user or account. In one embodiment, the user identificationis implicitly included, such as via a signing and/or encrypting key orcertificate. In another embodiment, the user identification isexplicitly included in the form of user credentials such as a usernameand password. In another embodiment, the user identification is derivedfrom other information, such as the address from which the request wasreceived. In another embodiment, no user identification is included inthe message. In such an embodiment, a default user identification may besubstituted.

At time 706, the Compute Controller 620 sends a message to Auth Manager630 to authenticate and authorize the request. The Auth Manager 630performs a check to see if the request is allowable. In one embodiment,this involves checking a permissions database to determine whether theuser identified by the user identification has permission to perform therequested operation. For example, in such an embodiment, the permissionsdatabase may allow user A to start VMs of a first type but not a secondtype, or may allow the user to only start VM images that it owns. Inanother embodiment, the check includes only determining if the useridentified by the user identification is an authorized user on thesystem. Also at time 706, the Compute Controller 620 performs a lookupto retrieve any default permissions the user has configured forcontrolling identity-based authentication (for example, as describedabove with reference to time 701).

At time 708, Auth Manager 630 sends back a response to ComputeController 620 indicating whether the request is allowable. The responsefrom the Auth Manager 630 to the Computer Controller 620 also includesany default permissions the user has configured for identity-basedvirtual machines. If the request is allowable, a message is sent to theCompute Manager 670 to instantiate the requested virtual machine at time710. At time 712, the Compute Controller 620 selects a Compute Worker676 and instructs it to instantiate the requested VM image. At time 714,the Compute Worker 676 loads the requested VM image from the ImageService 644.

At time 716, the Compute Worker 676 uses the available virtualizationinfrastructure as described relative to FIG. 2 to instantiate VMinstance 718 from the VM image loaded at time 714. Also at time 716, theCompute Worker assigns the VM instance 718 a MAC address 720 (orlink-local address). In one embodiment, the MAC address 720 is selectedfrom a pool of MAC addresses. In another embodiment, the MAC address 720is specifically configured for that VM instance, such as in the messagefrom the Compute Manager 670. In another embodiment, the MAC address 720is replaced with another immutable value that can be used to convey theidentity of VM instance 718. Such values include, but are not limitedto, an IP address, an IP port, a signature value, a unique identifier,or any other value known in the art. In one embodiment, the immutablevalue is a hash value computed from the VM image used to instantiate theVM instance 718, such as, for example, an SHA-1, SHA-2, or SHA-3 hash.In one such embodiment, the hash is computed at instantiation time andthen assigned as an immutable attribute of the VM instance 718 by theCompute Worker. In another embodiment, the compute node on which the VMinstance 718 is instantiated serves as the identity of the VM instance718. In another embodiment, the instructions performed by the VMinstance 718 themselves comprise the identity of the VM instance. Forexample, if the VM instance consisted of a set of executable codeinstructions, these code instructions are an immutable piece ofinformation about the VM instance, as they actually define what actionsthe VM instance performs. Changing them would result in a change to thefunctionality of the VM instance. Accordingly, in some embodiments, theidentity value may be computed based on an examination of thefunctionality or instructions executed by the VM instance 718.

In another embodiment, the VM instance 718 is assigned multipleidentities at instantiation. For example, the VM instance 718 may beassigned a MAC address and an SHA-1 hash value of its image. In one suchembodiment, the VM instance 718 provides the multiple identities as acombined value in order to authenticate to other components in thesystem. In another embodiment, the VM instance 718 provides only asingle identity value to each component in the cloud computing system towhich it needs to authenticate. In such an embodiment, each componentwould determine which identity value it required for authentication. Forexample, a network controller may require authentication via a MACaddress, while a metadata service may require authentication via a hash.In another embodiment, the APIs between the various components definewhich authentication methods are appropriate. In another embodiment, thecomponents accept multiple types of identities for authentication. Instill another embodiment, the components may allow authentication withone type of identity for certain types of data, and other types foranother. For example, network configuration information may require MACaddress authentication, while information relating to a particularvirtual machine image may require has authentication.

At time 722, the newly instantiated VM instance 718 begins the processof obtaining its initial configuration by interacting with MetadataService 724 and Network Controller 660. Metadata Service 724 is aservice that provides general configuration information to the newlyinstantiated VM instance 718. For example, the Metadata Service 724 maysupply the VM instance 718 with contact information (e.g. networkaddresses) for various other services or VMs with which it needs tointeract, configuration parameters that alter the mode or mechanism ofoperation of the VM instance 718, supplemental instructions to beexecuted on startup by the VM instance 718, or any other necessaryconfiguration information. The Metadata Service 724 applies permissionsconfigured by the user at step 701 to allow or deny the VM instance 718access to its resources based on the assigned MAC address 720. Forexample, depending on the permissions for its assigned MAC address 720,the VM instance 718 may be allowed to perform non-destructive actionslike listing available resources, but may be restricted from takingaffirmative actions such as spawning new VM instances. In embodimentsthat do not use a MAC address to denote the VM instance 718's identity,the Metadata Service 724 will be altered to apply the permissionsaccording the chosen identity mechanism. In one embodiment, the MetadataService 724 applies the permissions by interacting with the Auth Manager630, which determines whether to permit or deny access to the MetadataService 630 based on the MAC address.

In one embodiment, the VM instance 718 authenticates to the MetadataService 724 via an identity as described above. The Metadata Service 724responds with supplement, “possession-based” authentication informationsuch as a username and password, token, or other mechanism. In such atwo-stage authentication scheme, the identity is used only to prove thatthe VM instance 718 is entitled to possess the supplemental securitycredentials. Once the VM instance 718 initially proves its identity tothe Metadata Service 724, it can be issued the possession-basedcredentials and use those credentials for subsequent authentication toother resources.

At time 726, VM instance 718 interacts with Network Controller 660 toget a proper VLAN and IP address as described in steps 451-457 relativeto FIG. 4. The VM instance 718 again provides its MAC address 720 inorder to authenticate itself to the Network Controller 660 and obtainthe VLAN and IP address. In embodiments that do not use a MAC address todenote the VM instance 718's identity, the Network Controller 660 willbe altered to apply the permissions according the chosen identitymechanism. In one embodiment, the Network Controller 660 applies thepermissions by interacting with the Auth Manager 630, which determineswhether to permit or deny access to the Metadata Service 630 based onthe MAC address.

At time 728, the VM instance 718 and Compute Worker 676 interact todetermine whether the VM instance has been successfully instantiated. Inone embodiment, the VM instance 718 sends the Compute Worker a messageindicating successful instantiation. In another embodiment, the ComputeWorker 676 monitors the VM instance 718 to determine its status. At time730, an indication of the result of the instantiation request is sent bythe Compute Worker to the Compute Manager 670. At time 732, the ComputeManager sends the result to the Compute Controller 620. At time 734, amessage is sent back to the API Server 610 with the result. At time 799,the API-specified response to the original command is provided from theAPI Server 610 back to the originally requesting entity. If at any timea requested operation cannot be performed, then an error is returned tothe API Server at time 790 and the API-specified response to theoriginal command is provided from the API server at time 792. Forexample, an error can be returned if a request is not allowable at time708, if a VLAN cannot be created or an IP allocated at time 726, if animage cannot be found or transferred at time 714, etc.

Although the above embodiment describes a VM instance authenticating viaits identity to a network controller and a metadata service, the presentdisclosure is not limited to such an application. Authentication betweendifferent components in a cloud computing system can be performed usingan identity-based approach. For example, such an approach is useful in amulti-vendor cloud environment, where each component may be provided bya different party. In order to ensure cooperation and segregation ofresources in such an environment, it is important for the components tobe able to reliably identify each other.

For example, in one embodiment, identity-based authentication is used bya first hypervisor to determine whether to service the request of asecond hypervisor. Consider a configuration where each hypervisor has anidentity, and the first hypervisor receives a request from the secondhypervisor to spawn a VM instance to perform a certain task. Forexample, the second hypervisor is at capacity and requests the firsthypervisor to process a work unit it is unable to process in a loadsharing process. In such a configuration, the first hypervisor wouldexamine the identity of the second hypervisor to determine if it waswilling to process work units from the second hypervisor. For example,the first hypervisor might determine whether the second hypervisor'sidentity is in a group of identities for which the owner has paid forthe right to use the first hypervisor's spare resources. If so, it wouldprocess the request. If not, it would deny.

In another embodiment, communications and requests between individualVMs can be authenticated by identity. A first VM instance can determinewhether or not to trust information from a second VM instance based onthe identity value of the second VM instance. If it receives informationfrom an untrusted identity, it can discard it. In another embodiment, aVM instance authenticates to volume using an identity. In such anembodiment, the information returned from the volume is specific to theidentity of the VM instance. In another embodiment, the volume allowsthe VM instance to access a portion of its storage dedicatedspecifically to the VM instance's identity (e.g. a home directory).

In another embodiment, a compute worker authenticates to the imageservice via an identity (e.g. a MAC address) in order to retrieve an VMimage to instantiate. Such a scheme could be implemented in order toenforce security and allow only compute workers for a certain vendor orentity instantiate VM instances belonging to that entity in amulti-vendor cloud computing environment. In another embodiment, computecontrollers from different vendors or entities in a multi-vendorenvironment authenticate to each other via identities in order to shareusage information, distribute work units, and/or distribute and provideresources between each other. In another embodiment, a compute workerauthenticates requests from compute controllers based on the identity ofthe compute controller, again to allow for selective work unit servicingin a multi-vendor cloud computing environment.

In one embodiment, all identity-based authentication is performed by theAuth Manager 630, which is responsible for storing permissions for allidentities, role assignments, and all other configuration related toidentity-based authentication. In another embodiment, identity-basedauthentication is performed by a plurality of Auth Managers, each onecontaining a replicated copy of the identity and permission data. Inanother embodiment, the individual components, such as the NetworkController and Metadata Service, perform the identity-basedauthentication themselves and store the necessary identity andpermission data. In another embodiment, each vendor within amulti-vendor cloud computing system has its own Auth Manager 630 toperform identity-based authentication. In another embodiment, identitiesand permissions are selectively synchronized between Auth Managersbelonging to different vendors.

Turning now to FIG. 8, a flowchart showing one embodiment of a method800 according to various aspects of the present disclosure. At step 802,the user sets up default permissions for MAC-based authentication. Asdiscussed previously, other mechanisms for establishing identity besidesMAC address can be used without deviating from the teachings of thepresent disclosure. At step 804, the user registers these defaultpermissions with the Auth Manager. At step 806, the API Server receivesa request from the user to create and run a VM. At step 808, the APIServer relays the request to the Compute Controller. At step 810, theCompute Controller authenticates user with the Auth Manager andretrieves permissions set by user for MAC-based authentication. At step812, the Computer Controller messages the Compute Manager to instantiatethe VM. At step 814, the Compute Manager directs a Compute Worker toinstantiate the VM. At step 816, the Compute Worker loads the VM imagefrom the Image Service. At step 818, Compute Worker performs initialboot of the VM and assigns it a MAC address. At step 820, the VM usesthe MAC address to authenticate itself to various configurationresources and configure itself. At step 822, the VM is configured andready for regular use. Note that in other embodiments, various steps ofmethod 800 may rearranged, combined or omitted without deviating fromthe teachings of the present disclosure.

One advantage of identity-based authentication is that it allowsinteraction between interaction between a cloud computing system and VMsbased upon APIs. Identity-authenticated VMs can expose the public API onthe private VLAN network, and they may include extensions or early-stageAPIs that are not otherwise available, or other interactive setups.Making more of the VM instantiation process API-based increases theflexibility and capability.

Another advantage of identity-based authentication is increased securityand privacy for users of the cloud computing system. MAC addresses andother identity attributes are not easily spoofed, unlike traditionalpossession-based authenticators like user names and passwords. Inaddition, identity-based authentication allows the user to avoid codingsensitive information (such as login credentials) into a VM image thatmay be viewable by other users or system administrators.

Another advantage of identity-based authentication is it addresses thedifficult problem of authentication during initial setup of a virtualmachine instance in a cloud computing system. Identity-basedauthentication removes the need for storing user credentials orencryption keys with a virtual machine image for authentication. Withidentity based authentication, the virtual machine instance is providedwith a unique, immutable value that it can use to authenticate toresources on startup.

Another advantage of identity-based authentication is the ability toprovide secure authentication and authorization of components within amulti-vendor cloud computing system. In such a configuration, resourcesowned by the various vendors are often selectively shared based on whohas issued the request. Identity-based authentication can be used insuch a scenario to only service requests for service from vendors thatare authorized to receive such a service. For example, a vendor mightonly provide a service to other vendors or users within a cloudcomputing system if the users or vendors have paid a fee. Identity basedauthentication can be used to register the authorized identities toreceive the service based on receipt of payment.

Even though illustrative embodiments have been shown and described, awide range of modification, change and substitution is contemplated inthe foregoing disclosure and in some instances, some features of theembodiments may be employed without a corresponding use of otherfeatures. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the scope of theembodiments disclosed herein.

What is claimed is:
 1. A cloud computing system, the system comprising:a resource having configuration information; a virtual machine instanceoperably coupled to the resource, wherein the virtual machine instancehas an identity; and an authentication manager configured toauthenticate the virtual machine instance based on the identity of thevirtual machine instance, without storing credentials for authenticationof the virtual machine instance with the virtual machine instance. 2.The cloud computing system of claim 1, wherein the identity is a MACaddress.
 3. The cloud computing system of claim 1, wherein the resourceis a second virtual machine instance.
 4. The cloud computing system ofclaim 1, wherein the resource is a metadata service configured to storeconfiguration information.
 5. The cloud computing system of claim 1,wherein the resource is a network controller configured to providenetwork configuration information to the virtual machine instance. 6.The cloud computing system of claim 1, wherein the authenticationmanager is further configured to allow a user to setup permissions forthe identity, and to control access by the virtual machine instance tothe resource based on the permissions.
 7. The cloud computing system ofclaim 1, wherein the authentication manager is further configured toallow a user to setup permissions for a group of identities.
 8. Thecloud computing system of claim 1, wherein the authentication manager isconfigured to permit access to the resource based on whether the virtualmachine instance is authenticated.
 9. A method for controlling access toa resource, the method comprising: instantiating a virtual machineinstance; assigning an identity to the virtual machine instance;receiving a request for access to the resource from the virtual machineinstance, the request including the identity of the virtual machineinstance; determining whether to authenticate the virtual machineinstance based on the identity in the request, and authenticating, basedon the determining, the virtual machine instance, without storingcredentials for authentication of the virtual machine instance with thevirtual machine instance.
 10. The method of claim 9, further comprising:permitting the virtual machine to access the resource based on theresult of the determining step.
 11. The method of claim 9, furthercomprising: denying the virtual machine instance access to the resourcebased on the result of the determining step.
 12. The method of claim 9,further comprising: receiving permission information from a user, thepermission information defining access rights to the resource for theidentity; wherein the determining step further includes determiningwhether the virtual machine instance may access the resource based onthe permissions information.
 13. The method of claim 9, wherein the stepof assigning an identity to the virtual machine instance is performedbefore the step of instantiating the virtual machine.
 14. The method ofclaim 9, wherein the step of assigning an identity to the virtualmachine instance is performed after the step of instantiating thevirtual machine.
 15. The method of claim 9, wherein assigning theidentity to the virtual machine instance includes assigning a MACaddress to the virtual machine instance.
 16. A method for controllingaccess of virtual machines to resources in a cloud computing system, themethod comprising: receiving a request to instantiate a virtual machineinstance; instantiating the virtual machine instance; assigning thevirtual machine instance a unique, immutable attribute; performing aninitial boot of the virtual machine instance; receiving a request fromthe virtual machine instance to access a resource, the request includingthe unique, immutable attribute; determining whether to authenticate thevirtual machine instance based on permissions configured for the unique,immutable attribute assigned to the virtual machine instance;authenticating, based on the determining, the virtual machine instancewithout storing credentials for authentication of the virtual machineinstance with the virtual machine instance; if the virtual machine isauthenticated, transmitting a response to the virtual machine instance;and if the virtual machine is not authenticated, transmitting an errorresponse to the virtual machine instance.
 17. The method of claim 16,wherein assigning the unique, immutable attribute includes assigning aMAC address.
 18. The method of claim 16, wherein the step of assigningan identity to the virtual machine instance is performed after the stepof instantiating the virtual machine.
 19. The method of claim 16,wherein the step of assigning an identity to the virtual machineinstance is performed before the step of instantiating the virtualmachine.
 20. The method of claim 16, wherein determining whether toauthenticate includes determining whether a type of the request isincluded in a set of request types that are allowed for an access levelassociated with the unique, immutable attribute.